A Kind of Healthy Grave

Mann's mordantly witty new novel surpasses the acclaimed sleuthing adventures of British spy Tamara Hoyland in The Sting of Death and others in this series. Using her cover as an archeologist, Hoyland infiltrates the company of Dame Viola Hutber's ""Watchwomen,'' a repressive group who consider themselves guardians of their country's morals. She interviews Viola's brother Basil, headmaster of a posh school, notorious Lady Chantal Digby and others who may provide information about an ``accidental'' death in 1929. At that time, an artist named Rex was killed in a fire and his child model, known only as Stella, vanished. During the ensuing 60 years, an unsuspected murderer has done away with people linked to Rex, convicted of pornography during his life but now judged a genius. Hoyland follows a serpentine trail through an investigation that proves her as cunning and ruthless as her quarry. And proving her skills as a superb plotter, the author ends the mystery with the force of a whiplash. (December 22)